path: root/Documentation/kobject.txt
diff options
authorBjorn Helgaas <>2013-12-05 17:38:00 -0700
committerGreg Kroah-Hartman <>2013-12-07 21:20:11 -0800
commit35a5fe695b07ae899510ad76fdf0aeaef85fe951 (patch)
treecc91df4f94e06196faa9bde4c6d5cb50fd94bc07 /Documentation/kobject.txt
parent89c86a64cd056e283323710c9ddf6f7090a450c8 (diff)
kobject: remove kset from sysfs immediately in kset_unregister()
There's no "unlink from sysfs" interface for ksets, so I think callers of kset_unregister() expect the kset to be removed from sysfs immediately, without waiting for the last reference to be released. This patch makes the sysfs removal happen immediately, so the caller may create a new kset with the same name as soon as kset_unregister() returns. Without this, every caller has to call "kobject_del(&kset->kobj)" first unless it knows it will never create a new kset with the same name. This sometimes shows up on module unload and reload, where the reload fails because it tries to create a kobject with the same name as one from the original load that still exists. CONFIG_DEBUG_KOBJECT_RELEASE=y makes this problem easier to hit. Signed-off-by: Bjorn Helgaas <> Signed-off-by: Greg Kroah-Hartman <>
Diffstat (limited to 'Documentation/kobject.txt')
1 files changed, 4 insertions, 1 deletions
diff --git a/Documentation/kobject.txt b/Documentation/kobject.txt
index c5182bb2c16c..f87241dfed87 100644
--- a/Documentation/kobject.txt
+++ b/Documentation/kobject.txt
@@ -342,7 +342,10 @@ kset use:
When you are finished with the kset, call:
void kset_unregister(struct kset *kset);
-to destroy it.
+to destroy it. This removes the kset from sysfs and decrements its reference
+count. When the reference count goes to zero, the kset will be released.
+Because other references to the kset may still exist, the release may happen
+after kset_unregister() returns.
An example of using a kset can be seen in the
samples/kobject/kset-example.c file in the kernel tree.